Documentaries don’t have to be technically great to be irresistible, and Bess Kargman’s First Position, which follows six young ballet dancers as they prepare for an elite competition, is a case in point.

As we near the end of a summer season stuffed to bursting with big, ambitious comic-book movies — from the buffed, Wagnerian pecs of Thor to the pompous clutter of Green Lantern — here comes Captain America: The First Avenger, limping behind the rest of the parade.